A disk drive, such as a magnetic disk drive, comprises a magnetic disk, spindle motor, magnetic head, and carriage assembly. The magnetic disk is disposed in a base. The spindle motor supports and rotates the disk. The magnetic head reads and writes data from and to the disk. The carriage assembly supports the head for movement relative to the disk. The carriage assembly comprises a rotatably supported arm and a suspension extending from the arm, and the magnetic head is supported on an extended end of the suspension. The head comprises a slider mounted on the suspension and a head section disposed on the slider. The head section comprises a recording element for writing and a reproduction element for reading.
Magnetic heads for perpendicular magnetic recording have recently been proposed in order to increase the recording density and capacity of a magnetic disk drive or reduce its size. In one such magnetic head, a recording head comprises a main pole configured to produce a perpendicular magnetic field, return or write/shield pole, and coil. The return pole is located on the trailing side of the main pole with a write gap therebetween and configured to close a magnetic path that leads to a magnetic disk. The coil serves to pass magnetic flux through the main pole.
In recording a record pattern along a track of the magnetic disk, recording magnetic fields also simultaneously leak from the opposite sides of the main pole transversely relative to the track. There is provided a head that comprises side shields arranged individually on the opposite sides of the main pole transversely relative to the track, whereby the leakage magnetic fields are reduced.
In recording data in a perpendicular recording medium by means of the magnetic head for perpendicular recording constructed in this manner, a substantially perpendicular magnetic field is formed on a surface of the medium just below the main pole. This magnetic field returns to the return pole through a soft magnetic layer below a recording layer of the perpendicular recording medium. However, a certain region just below the return pole includes an area on which magnetic fields are concentrated. In some cases, the concentrated magnetic fields may destabilize magnetization of the recording layer and erase or degrade recorded data.